Sulphate black liquor talloel rosin and process of making the same



Patented Feb. 20, 1940 "S ULPHATE BLACK LIQUOR TALLOEL PROCESS- F MAKING THE 6' Torsten Hasselstrom, New York, N Y.

No Drawing.

Application January 8, 1935, Serial No. 845 V P 4 Claims. (01. 260-107) I The present invention relates to sulphate black liquor talloel rosin, and, more particularly, to refined sulphate black liquor talloel rosin and to a process, of producing such refined talloel rosin 5 on an industrial scale.

It is well known in the paper and pulp industry that when black liquor from the sulphate process is evaporated, a scum, known as talloel soap, separates and floats upon the surface of the black liquor. The talloel soap which isskimmed off the evaporated black liquor is ready for treatment. The customary procedure is to add dilute sulphuric acid. Following this addition of acid, the mass separates into two layers, the upper of which contains crude talloel. Many efforts have been made to use crude talloel directly in commerce and industry in a practical and satisfactory manher, and to provide processes of treating the crude talloel to make it available for'satisfactory use 20 in commerce andindustry. These prior efforts have been unsuccessful for one reason or another and no completely successful and wholly satisfactory process has been provided for converting crude talloel into an industrially and commer- 25 cially useful and satisfactory product.

I have discovered a process of treating "sulphate black liquor or the talloel soap'obtained therefrom to produce a refined'talloel and a rosin substitute possessing properties which make it 30 valuable -and useful as a commercial and industrial product.

It is an object of the invention to provide a simple, economical and practical process for carrying out my discovery on an industrial scale.

It is also within the contemplation of the invention to provide a process which is capable of being operated by relatively unskilled labor and which is capable of producing useful and valuable by-products including crude and refined talloel 40 rosin.

Other objects and advantages will become apparent from the following description of a preferred procedure for carrying the present invention into practice.

Black liquor produced in the sulphate process of producing pulp and paper is used as the raw material and is termed herein sulphate black liquor for convenience. The black liquor is evaporat ed until the talloel soap separates. The exact 50 specific gravity to which the black liquor must be evaporated before the talloel soap separates depends upon the alkalinity and viscosity of the black liquor as one skilled in the art readily understands. When the black liquor has been 5 evaporated as aforesaid, crude talloel coap separates and floats on the surface of theevaporated liquor. By skimming off the floating scum, crude talloel soap may be obtained.

The crude talloel soap is treated with a suitable acid or acid substance, such as sulphuric acid or 5 acid sodiumsulphate, to liberate crude talloel. In practice dilute sulphuric acid having a concentration of about 10-20% or an eight normal solution of acid sodium sulphate has been found to give satisfactory results. After the acid has 10 reacted with the crude talloel soap and has been permitted to settle, the mixture separates into two layers. The crude talloel is in the upper layer and can be obtained by separating the upper and lower layers from each other. For instance, the upper layer can be removed from the lower layer by syphoning or by any other suitable procedure well known to those skilled in the art.

I have found that the crude talloel, which is not very useful, can be converted into a highly useful refined product by removing certain constltuents. These constituents can be removed satisfactorily by permitting the-talloel to stand for a period of time, say about 2 days to about 10 days or so at atmospheric temperatures. Among the constituents, which'are practically completely removed, may be mentioned ligneous matters and higher saturated fatty acids. In addition, the refined product contains reduced amounts of oxidized colophonic acids and colophonic acids (classified according to Aschans system) and reduced amounts of non-saponifiable matter than the crude talloel. In practice, the foregoing constituents separate out from the talloel on standing and may be removed by filtering, decanting, or the like. The filtrate is refined talloel which is relatively stable and which is very useful commercially and industrially. Among the important uses, I have discovered for refined talloel, soap making and flotation of certain ores of the alkaline earth metals may be mentioned. This latter discovery is described and claimed in copending applications, Serial No. 578,842, filed December 3, 1931 (United States Letters Patent No. 1,986,816), and Serial No. 648,215, filed December 21, 1932 (United States Letters Patent No.

In some instances, the refining operation may be carried still further. For instance, by refrigerating the talloel at a temperature within the range of about 25? C. to about minus 10 C., say about 0 C. and maintaining it at the refrigerated temperature for a period of say a week to ten days or so, with or without aeration, it is possible to remove further constituents from the talloel.

moved. The filtrate is a super-refined talloel and is useful and available for additional purposes. Thus, it may be used for making laundry and other soaps. I

In the event it is desired to de-colorize my refined or super-refined talloel, it may be-accomplished in any appropriate or'well known manner. Forinstance, the refined or super-refined talloel may be .decolorized with carbon, fullers earth, sulphur dioxide or the-like in" accordance 3 I crystals can be obtained.

with well known procedures.

It has also been found that the solids separated from the liquid talloel can be melted together to form a product which can be used as a substitute for rosin. The solids may be used separately for the aforesaid purpose,'if it is desired. It will thus be observed that the by-products are useful and valuable instead of being useless.

The aforesaid solids separated from the liquid ta1loel,-sometimes called press cake, were found to contain a large amount of resin acids in addition to ligneous matter and higher fatty acids. It was discovered that the resin acids can be isolated by means of crystallizing the press cake from a suitable solvent. Satisfactory results were obtained with lower alcohols such as methanol,

,ethanol, propionol, butanol, with benzol; with acids are crystallized from the mother liquor-by esters of paraflln hydrocarbons such as ethyLacetate, butyl acetate, etc., with acetic acid, with acetone and the like. In carrying the foregoing operation into practice, the press cake is dissolved in the solvent and is then filtered to separate the insoluble residue from the dissolved portion. Some of the solvent is evaporated and the resin permitting it to stand. These resin acid crystals are then separated by filtering from the mother liq or. It is preferred to wash them with the sa e kind of solvent as first used or with any other appropriate solvent for washing purposes.

The resin acids thus obtained are then fused, say at about 150- l70 C., in order to produce a high grade substitute for colophony which can be used for all purposes .where common wood or gum rosins are used.

It was found that a more convenient method for commercial use for isolating the resin acids from the press cake is as follows: The press cake is distilled under a vacuum at about 20 to mm. pressure and at a temperature of about 240 to 280 C. This procedure is carried out for a prolonged period, preferably about 4 to about 10 hours. The distillate obtained from the foregoing operation contains a rosin substitute having Q a light color. The rosin substitute which is thus "pbt'ained is more stable to light and air than comarnon wood or gum rosin known as colophony. In

other words, the present invention provides a superior grade of rosin substitute. The present invention also contemplates the provision of a process to produce crystalline resin acids by means of crystallizing the rosin substitute froman appropriate solvent, such .as those mentioned hereinabove and subjected to the process described hereinbefore.

For the purpose of giving those skilled in the art a better understanding of carrying the invention into practice, the following illustrative examples will be given:

Example No. 1 About 200 grams of solids separated from the refined talloel is subjected to distillation at 20 mm. pressure and the following fractions are obtained from the distillate:

1. A fraction up to about 238 C. yields about 48.0 grams of higher fatty acids and decomposition products.

2. A fraction from about 240 to about 260 0. yields about 143.5 grams of water white solid rosin substitute.

3. A residue of pitch amounting to about 20.0

grams. a

By treating the second fraction'of 143.5 grams of rosin substitute with a solvent, such as methanol, a yield of about 50.0 grams of resin acid Eicample No. 2

About '700 grams of'solids obtained from the refined tailoel as set forth hereinabove and having an acid number of 176.0 was subjected to distillation for about 6 hours under the following conditions to produce the. following fractions:

1. A fraction at a temperature of about 254 C. and under a pressure about 40 mm. of mercury gives a yield 50 grams of fatty acids with an acid number of 267.4. s.

2. A fraction at a temperature of about 254 to about 257 C. and under a pressure of about 80 mm. of mercury gives a yield of about grams of fatty acids with an acid'number of 140.9.

3. A fraction at atemperature of about 256 to about 278 C. and under a'pressure of about 80 mm. of mercury gives a; yield of about 280 grams soft rosin substitute with an acid number of 143.9.

4. A residue of pitch remained amounting to about 84 grams and having a low acid number.

The main fraction (3) lconsisted of a rosin substitute which was soft but imving a light color. From this fraction,'r.esin acids or an acid mixture was separated which on recrystallizing once from methanol melted at about 164 to about 169 0., had an optical rotation of about [a]n =+24.8, and possessed an elemental formula of CzoHsoOz.

From the foregoing, it will be observed that preferred procedures of carrying the present in- 280? C. and under a vacuum of about 20 to about 80 mm. of mercury. The distilling time is about 4 to about 10 hours which includes the initial heating period.

2. The fraction of about 240 to about 280 C.,

is the most valuable fraction and constitutes a rosin substitute. This fraction is a water white resin grade which is valuable commercially.

3. A crystallization of the rosin substitute produces an acid which in a crude state has a melt-,

ing point of about 164 to about 169 C., an optical rotation of [a]n2-z=+24.8, andan elemental formula of C2oH3oO2.

It will be observed that the present invention provides a process of producing a refined talloel which is purified and which has a fairly low viscosity, which can be pumped like a liquid and which can be shipped in barrels and tank cars as an article of commerce." i

It will be noted that the present invention provides a refined talloel which is purified and .which has the following properties;v My refined talloel is substantially devoid of ligneous matters and/or higher saturated fatty acids of sulphate black liquor, and contains reduced amounts of colophonic acids, oxidized colophonic acids 1. and/or non-saponifiable matter. The acid number varies but is approximately 190 to about 200. In the same way, the iodine number varies but is approximately 200 to about 210 according to the Hanus method. The specific gravity at about C. is more than about 0.89 and less than about 1.00. The viscosity is fairly low; the color varies but is usually reddish brown; and the odor somewhat resembles that of a mixture of pine oil and rosin. Moreover, the refined talloel is relatively stable as an article of commerce and practically no solid matter separates upon standing for a reasonable length of time, say about two weeks to about ten weeks.

It will be further noted that the present invention provides a purified and super-refined talloel which has the following properties: The acid number varies but is approximately 180 to about 190. Similarly, the iodine number varies but is approximately 165 to about 1'75 according to the Hanus method. The specific gravity varies from about 0.90 to about 0.97 at about 20 C. The super-refined talloel has a fairly pleasant odor resembling that of a mixture of pine oil and rosin, has a reddish yellow to yellow color and is substantially devoid of ligneous matter, and/or higher saturated fatty acids of sulphate black liquor. The viscosity is less than that of my refined talloel. Practically no solid matter sepa-' rates upon standing for a reasonable length of time, such as two weeks to ten weeks, and the super-refined talloel is a relatively stable article of commerce. Furthermore, the super-refined talloel contains smaller amounts of colophonic acids, oxidized colophonic acids and/or nonsaponifiable matter and/or resin acids than my refined talloel.

Although the invention has been described. in connection with a preferred embodiment, it will be observer that variations are within the purview of the appended claims. For example, artificial cooling or refrigeration may be used in the first operation in order to eifect a separation of certain of the constituents from the crude talloel. It is to be observed, however, that temperatures lower than about minus 10 C. should not be employed. Other modes of separating my refined or super-refined talloel from the undesirable solid constitutents mentioned hereinabove may be employed, such as vacuum distillation with or without the use of steam. Furthermore, filter aids, such as kieselguhr, sil-o-cel, diatomaoeous earth, and the like, may be employed to facilitate filtration or separation of the undesired solid constituents.

It is to be noted that the raw material or crude talloel soap is obtained from black liquor of the sulphate process of paper or pulp making. This process is well known to chemists and is not to be confused with the sulphite process or other processes. The liquor obtained from these processes would not yield my refined talloel or super-refined talloel.,

The present application is a continuation in part of my co-pending application, Serial No. 578,841, filed on December 3, 1931 (United States Letters Patent No. 1,986,815).

I claim:

1. The process for producing solid talloel rosin from crude talloel soap of sulphate black liquorwhich comprises reacting crude talloel soap with an aqueous acid solution to form a liquid mass containing crude talloel, removing said crude talloel from the aqueous mass, crystallizing resin acids from said crude talloel whereby solid crude rosin separates, isolating said solid crude talloel rosin having an acid number greater than 150 containing a resin acid-having an elemental formula approximating CzoHsoOz and having a negative sign of optical rotation, distilling said solid crude talloel rosin in the absence of solvents under a vacuum of about 20 mm. to about 80 mm. pressure, and isolating a fraction distilling under said vacuum at about 240 C. to about 280 C. to produce a purified rosin containing a resin acid having a positive sign of optical rotation.

2. The process for producing solid talloel rosin from crude talloel soap of sulphate black liquor which comprises reacting crude talloel soap with an aqueous acid solution to form a liquid mass containing crude talloel, removing said crude talloel from the aqueous mass, crystallizing resin acids from said crude talloel whereby solid crude rosin separates, isolating said solid crude talloel rosin containing a resin acid having an elemental formula approximating C20H3o02 and having a negative sign of optical rotation, distilling said solid crude talloel rosin in the absence of solvents under vacuum of about 20 mm. to about 80 mm. pressure, isolating a fraction distilling under said vacuum at about 256 C. to about 278 C. to produce a purified rosin containing the aforesaid resin acid, dissolving said purified rosin in methanol, and crystallizing a further purified rosin having a melting point of about 164 C. to about 169 C. and an optical rotation of about and containing the aforesaid resin acid with an elemental formula of CzoHaoOz.

3. The process for producing solid talloel rosin from crude talloel soap of sulphate black liquor which comprises reacting crude talloel soap with an aqueous solution more acid than carbon dioxide to form a liquid mass containing liquid crude talloel, removing said liquid crude talloel from the aqueous mass. crystallizing colophonic acids contaminated by oxidized colophonic acids, higher fatty acids, ligneous matter, odorous bodies and sterols to form solid crude talloel rosin having an acid number about 176 and containing a resin acid having an elemental formula approximating CzoHacOz and having a positive sign of optical rotation and separating higher fatty acids, ligneous matter, odorous bodies and sterols from said solid crude talloel rosin whereby a refined solid talloel rosin containing the aforesaid resin acid is obtained.

4. The process for producing solid talloel rosin from crude talloel soap of sulphate black liquor which comprises reacting crude talloel soap with an aqueous acid solution to form a liquid mass containing crude talloel, removing said crude talloel from the aqueous mass, crystallizing resin acids from said crude talloel whereby solid crude rosin separates containing colophonic acids, oxi- 

